Electronic device and method of manufacturing the same

ABSTRACT

Provided are an electronic device including a bank structure and a method of manufacturing the same. The method of manufacturing the electronic device requires a fewer number of processes and comprises a direct patterning of insulating layers, such as fluorinated organic polymer layers, is possible using cost-efficient techniques such as inkjet printing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of European Patent Application No.06 126 004.8, filed on Dec. 13, 2006 and Korean Patent Application No.10-2007-0036180, filed Apr. 12, 2007, the disclosures of which areincorporated by reference in their entireties.

BACKGROUND

1. Technical Field

This disclosure relates generally to an electronic device and a methodof manufacturing the same, and more particularly, to an organic lightemitting diode comprising a bank structure and a method of manufacturingthe same; and also relates to an electronic device comprising a bankstructure having conductive lines and a method of insulating theconductive lines used in the electronic device; and further relates to amethod of forming a gate electrode of a thin film transistor (TFT) of anorganic light emitting diode (OLED) and an electrophoretic device.

2. Description of the Related Art

According to the present state of the art, there is no convenient methodof direct patterning insulating materials such as fluorinated organicpolymers. As used herein, the term “insulating material” is understoodto be a material with a breakthrough voltage of about 2.0 MV/cm or more.Therefore, it is desirable to provide a patterning method of insulatingmaterials, such as fluorinated organic polymers, using cost-efficienttechniques such as inkjet printing.

For example, in the manufacture of an organic light emitting diode(OLED) display device, liquid ink containing an organicelectroluminescent material can be applied onto pixel areas of the OLEDdisplay device. However, due to ink wetting issues, a bank structure isused in many inkjet patterning processes to provide the desired pattern,for example, to reduce ink overflow into adjacent pixel areas of theOLED display device. However, the manufacture of such a bank structurerequires the use of a photoresist in a photolithography process,followed by one or more fluorination processes to generate an efficientworking bank that comprises mechanical barriers, as well as a pattern ofhydrophilic and hydrophobic areas. Accordingly, processes that use bankstructures to avoid ink overflow results in a greater number of processoperations.

SUMMARY OF THE INVENTION

Some embodiments described herein provide a method of manufacturing anelectronic device including a bank structure requiring a fewer number ofprocesses in which a direct patterning of insulating layers, such asfluorinated organic polymers, is possible by using cost-efficienttechniques, such as inkjet printing, As well as an electronic devicemanufactured using the method.

Some embodiments comprise a patterning method that makes it simple toproduce many convenient structures, which reduces process operations,and increases the performance of an electronic device and a fill factorof display elements. With the new technique, it is possible to fabricatealignment structures for succeeding printing processes, e.g., in themanufacture of organic display devices. The reduction in processoperations by the use of patterned fluorinated organic polymers as aself-alignment (no wetting) layer for succeeding coatings is anadditional benefit. Furthermore, embodiments of the patterning methodare roll-to-roll compatible, and therefore, flexible substrates areprocessable therewith.

Some embodiments also provides a method of manufacturing an electronicdevice including applying an organic insulating layer including anorganic insulating material on a substrate, and patterning the organicinsulating layer by applying an organic solvent to the organicinsulating layer.

In some embodiments, the organic solvent is applied to the surface ofthe organic insulating layer that is coated with functional layers, suchas polymers and fluoropolymers. In some embodiments, the organic solventis preferably applied by inkjet printing, for example, as a stream ofdroplets.

The applied organic solvent dissolves some of the organic insulatingmaterial, and the solution of the dissolved material flows laterally dueto kinetic energy of the droplet of organic solvent. The ensuing solventdroplets dissolve more of the organic insulating material in the samearea, thereby thinning the area and forming a first groove, hole,hollow, or recess. The highly concentrated solution thus generated hasenough kinetic energy to exit from the resulting first groove formed inthe insulating layer. Because the organic solvent has a low boilingpoint, the organic solvent quickly evaporates and the dissolvedinsulating material quickly solidifies, accumulating in a second area atwhich solvent is not applied, thereby increasing the thickness of thelayer of organic insulating material at the second area. The second areais in the vicinity of, peripheral to, or adjacent to the first groove.Thus, protrusions are formed on the second area due to the accumulatedorganic insulating material.

This organic insulating accumulated material can, for example, be usedto cover conductive lines or as a bank for succeeding processes. Byusing fluorinated insulators and fluorinated solvents, self assembledstructures can be produced very easily, and that way, a patternedancillary can support succeeding patterning methods.

Subsequently, the organic insulating material may be completely orpartially removed using the organic solvent. Alternatively, the organicinsulating material may be partially removed from the first area byapplying the organic solvent and then completely removed using plasmaetching. A conductive layer may be formed on the patterned organicinsulating layer, and used as a conductive line, a gate electrode, apixel electrode, a capacitor electrode, or the like.

Embodiments of the method may further include forming a first conductivelayer on the substrate. Then, the organic insulating layer is formed onthe first conductive layer, and the organic insulating layer ispatterned to expose the first conductive layer by applying the organicsolvent to the organic insulating layer. An electroluminescent layer mayfurther be formed on the exposed first conductive layer. Thus, the firstconductive layer may be used as a pixel electrode of light emittingdevices.

Alternatively, the organic insulating layer is formed on the firstconductive layer, and then the organic insulating layer is patterned bypartially removing the organic insulating layer so as to not expose thefirst conductive layer. Then, a second conductive layer may be formed onthe patterned organic insulating layer. The first conductive layer, theorganic insulating layer, and the second conductive layer may be acapacitor device comprising a pair of capacitor electrodes and adielectric substance.

All in all, provided is a simple and fast, one-step patterning method toachieve several structures on coated materials, which is especiallyapplicable to organic electronics, which can further be formed onflexible substrates. Organic devices like OLED displays or organic thinfilm transistor (OTFT) circuits comprise many different active andinactive components, which are preferably produced at a low cost. Thisnew technology allows the production of many of these active andinactive components in a simple way with an improvement in performanceand a reduction in the number of process operations.

Furthermore, some embodiments provide an electronic device including asubstrate, and an organic insulating layer that is formed on thesubstrate and that comprises an organic insulating material, wherein theorganic insulating layer includes a first area having a first groove,and a second area having at least one protrusion that is to be connectedto the first groove.

As used herein, the term “protrusion” refers to a region having athicker organic insulating layer as compared to a region of the organicinsulating layer to which the organic solvent has not yet been applied.

The thickness of the organic insulating layer in the first area isreduced due to the organic solvent applied thereto in order to form thefirst groove, and the dissolved organic insulating material from thefirst area accumulates on the second area adjacent to the first area toform the protrusion. The second area may include a plurality ofprotrusions, and a second groove may be formed by the plurality of theprotrusions. By applying the organic solvent to the organic insulatinglayer, the organic insulating material of the first area is completelyor partially removed, thereby reducing the thickness of the organicinsulating layer from the initial thickness of the organic insulatinglayer. In contrast, because the second groove is formed by theprotrusions on the organic insulating layer, the thickness of theorganic insulating layer in the second groove is generally the same asor greater than the initial thickness of the organic insulating layer.Accordingly, the bottom of the second groove has a thicker organicinsulating layer than the bottom of the first groove.

The electronic device may further include a first conductive layerdisposed between the substrate and the organic insulating layer. Theorganic device may further include a second conductive layer that isformed in the first groove and/or the second groove, and/or encapsulatedby one or more of the protrusions. The second conductive layer may beused as a gate electrode, a pixel electrode, a conductive line, acapacitor electrode, and the like.

According to a first aspect, there is provided a method of manufacturingan electronic device including forming at least one layer including anorganic insulating material. The method includes providing a substrate;applying an organic insulating layer including an organic insulatingmaterial on the substrate; and applying an organic solvent directly ontothe organic insulating layer. The use of an organic solvent results in adirect patterning method that requires a fewer number of processoperations for manufacturing a bank structure for a display device,wherein the bank structure is used for a succeeding inkjet printingprocess for depositing a dissolved organic electroluminescent material.Preferably the thickness of the organic insulating material of the layeris reduced in a plurality of first areas by applying organic solvent ineach of the first areas, wherein no organic solvent is applied onto asecond area or onto a plurality of second areas, wherein each secondarea is defined as an area between adjacent first areas. Preferably eachfirst area is configured to form a pixel area of an organicelectroluminescent display, and each second area is configured to form anon-pixel area of an organic electroluminescent display. Therefore, abank structure comprising a plurality of pixel areas can be manufacturedby a direct patterning method. The first areas/pixel areas areconfigured to form mechanical barriers for an ink (to be printed) suchthat an ink overflow into adjacent pixel areas can be avoided during themanufacture of an OLED display, for example.

Therefore, preferably each first area is separated from an adjacentfirst area by a second area, and the thickness of the organic insulatingmaterial of the layer in each second area is greater than the thicknessof the organic insulating material of the layer in an adjacent firstarea. Preferably the organic solvent is applied onto a plurality offirst areas arranged in a matrix. Alternatively it is possible that theorganic solvent is applied onto a plurality of line-shaped first areasarranged generally parallel to each other, wherein each of theline-shaped first areas is configured to extend in a horizontal or in avertical direction of an organic electroluminescent display and whereineach pair of adjacent line-shaped first areas are generally disposed ata uniform distance from each other.

The thickness of the insulating layer is reduced in a first area ontowhich the solvent is applied, and the thickness of a neighboring secondarea is furthermore increased by the accumulation of dissolvedinsulating material. Such bank structures can comprise barriers that areup to ten times higher than the pixel areas. Therefore, preferably theorganic solvent is applied such that a thickness of the organicinsulating material of the layer in each second area is at least abouttwo times greater, more preferably, about five times greater, and stillmore preferably, about eight times greater, than the thickness of theorganic insulating material of the layer in an adjacent first area. Theexact reduction in the layer thickness of the layer in the first areasonto which organic solvent is applied can be controlled by parametersincluding: the material of the insulating layer, the starting thicknessof the insulating layer, the solvent, the amount of solvent applied inthe first area, as well as the surface dimensions of the first area. Bythe appropriate selection of the above mentioned parameters, it ispossible to completely remove the organic insulating material in thefirst areas or to only reduce the thickness of the organic insulatingmaterial in the first areas. By control of the above mentionedparameters, the ratio of the thickness of the organic insulatingmaterial in the first area and the second area can also be controlled.For the use of a bank structure for the manufacture of an organicelectroluminescent display, the first areas are preferably configuredsuch that a pitch or distance between the centers of two adjacent firstareas ranges between about 10 μm and about 150 μm, more preferablybetween about 30 μm and about 80 μm.

According to a second aspect, there is provided a method ofmanufacturing an organic electroluminescent display. The method includesproviding a substrate; applying a first electrode layer onto thesubstrate, wherein the first electrode layer is preferably an anodelayer; applying a layer of an organic insulating material onto the firstelectrode layer; and applying an organic solvent onto a plurality offirst areas or pixel areas, thereby dissolving and completely removingthe organic insulating material from the pixel areas such that the firstelectrode layer is exposed in the pixel areas. Furthermore, an organicelectroluminescent layer is applied in each of the pixel areas and asecond electrode is formed over the organic electroluminescent layer.Furthermore, it is preferred that the whole display device isencapsulated in order to prevent moisture and oxygen to deteriorate theorganic electroluminescent material. Preferably, the organicelectroluminescent layer consisting of an organic electroluminescentmaterial is applied onto each of the first electrode layers by inkjetprinting or spin coating. Furthermore, it is preferred to apply theorganic electroluminescent material onto the first electrode layer ineach of the first areas or pixel areas by dipping if fluorinated organicinsulating materials are used.

According to a third aspect, there is provided a method of manufacturingconductive lines. The method includes: providing a substrate; applying alayer of an insulating material onto the substrate; applying at leastone conductive line onto the layer of the organic insulating material;and applying an organic solvent to at least a portion of an areaneighboring the at least one conductive line, thereby accumulatingdissolved insulating material on an edge and/or outer portion of an areaonto which the solvent is applied, and thereby partially or completelycovering and encapsulating the at least one conductive line with thedissolved organic insulating material. Accordingly, a very easy processfor the encapsulation of conductive lines is provided. As alreadymentioned, the amount of accumulated material that is transported by theapplication of an organic solvent from an area onto which the solvent isapplied to a neighboring area or an edge area can be easily controlledby the selection of the organic insulating material and/or thicknessthereof, the organic solvent, amount of solvent, and/or surface areaonto which the solvent is applied. For the encapsulation of a conductiveline, it is preferred that at least one conductive line is formed with awidth between about 1 μm and about 200 μm, and with a height of betweenabout 0.03 μm and about 3 μm. More preferably, the width of the at leastone conductive line ranges between about 5 μm and about 50 μm, and theheight ranges from between about 0.1 μm and about 2 μm. Furthermore,preferably the area onto which the organic solvent is applied has adistance from the at least one conductive line of between about 10 μmand about 50 μm, more preferably, between about 20 μm and about 40 μm,and has a width in a direction perpendicular to the longitudinal axis ofthe at least one conductive line of between about 50 μm and about 500μm, more preferably, between about 100 μm and about 300 μm. Furthermore,it is also possible to encapsulate two or more conductive lines at onetime. In order to encapsulate two parallel conductive lines, organicsolvent is applied onto an area between the conductive lines. Therefore,at least two parallel conductive lines extending along a first directionare formed on the layer of an organic insulating material, and theorganic solvent is applied to at least a portion of an area between theat least two conductive lines, thereby dissolving organic insulatingmaterial in an area onto which the organic solvent is applied, andfurther covering the at least two parallel conductive lines withdissolved and accumulated insulating material at the same time.Preferably, the at least two parallel conductive lines are formed with awidth of between about 10 μm and about 50 μm, more preferably, betweenabout 20 μm and about 40 μm, and a height of between about 0.03 μm andabout 3 μm, more preferably, between about 0.1 μm and about 2 μm,wherein the distance between adjacent parallel conductive lines rangesbetween about 70 μm and about 500 μm, more preferably, about 100 μm andabout 400 μm. Furthermore, preferably the area onto which the organicsolvent is applied has a distance from each of the at least two parallelconductive lines between about 10 μm and about 50 μm, more preferably,between about 20 μm and about 40 μm, and the area onto which the organicsolvent is applied has a width in a direction perpendicular to the axisof the conductive lines of between about 50 μm to about 500 μm, morepreferably, between about 100 μm and about 400 μm. Furthermore, it ispossible to form additional conductive lines extending along a directionwhich is different from the direction of the conductive lines which havealready been covered with insulating material by the above-describedapplication of an organic solvent. More preferably, the additionalconductive lines which are formed over the encapsulated conductive lineshave a direction extending perpendicular to the direction of theencapsulated conductive lines.

As used herein, the terms “a first layer is applied on a second layer”or “a first layer is arranged on a second layer” or “a first layer isformed on a second layer” or “a first layer is formed above a secondlayer” refer to a first layer disposed directly on a second layer, aswell as to arrangements in which at least one third layer is disposedbetween the first and second layer.

According to a fourth aspect, an array of organic thin film transistorscan be easily manufactured by applying an organic solvent onto a layerof an organic insulating material. The method includes: providing asubstrate; applying a plurality of functional layers including a sourceelectrode, a channel area of semiconductor material, and a drainelectrode; and covering the functional layers with an organic insulatinglayer of an organic insulating material. Then, for each TFT, a gateelectrode layer is applied on the organic insulating layer in an areawhich is located above the channel area of each TFT. Then, an organicsolvent is applied in a first area neighboring the gate electrode,thereby accumulating material, which encapsulates the gate electrodewith the dissolved organic insulating material from the first area. Thefirst area in which the organic solvent is applied forms a first groove.Preferably, the organic insulating layer is formed with a thickness ofbetween about 0.1 μm and about 2 μm, more preferably, between about 0.5μm and about 1.5 μm, and at least one gate electrode is formed with awidth of between about 10 μm and about 300 μm, with a height of betweenabout 0.3 μm and about 3 μm, and wherein the distance between the atleast one gate electrode and the area in which the organic solvent isapplied ranges from between about 10 μm and about 50 μm, morepreferably, between about 20 μm and about 40 μm.

According to a fifth aspect, there is provided a display deviceincluding a thin film transistor coupled to a pixel electrode. Aplurality of functional layers including a source electrode, a channelarea, a drain electrode, and a pixel electrode are formed on asubstrate, and an organic insulating layer is formed to the cover thefunctional layers. Then, an organic solvent is applied to a first areaor pixel area of the organic insulating layer in which the pixelelectrode layers are located, thereby accumulating organic insulatingmaterial in a second area corresponding to an adjacent source electrodelayer and an adjacent drain electrode layer, thereby forming aprotrusion. A plurality of protrusions may be formed by applying theorganic solvent to both first areas neighboring a second area. Thus, asecond groove may be formed by adjacent protrusions in the second areaof the organic insulating layer, which corresponds to the channel area.A gate electrode is formed in each of the second grooves. Furthermore,the organic insulating material is preferably dissolved and completelyremoved from the first area onto which the organic solvent is applied,thereby forming a plurality of pixel areas. Preferably, a passivationlayer is formed over each of the plurality of gate electrodes.Preferably the organic insulating layer is formed with a thickness ofbetween about 0.1 μm and about 2 μm, more preferably, between about 0.5μm and about 1.5 μm, and the distance between the at least one grooveand the adjacent first area in which the organic solvent is appliedranges from between about 50 μm to about 500 μm, more preferably,between about 100 μm and about 400 μm.

According to a sixth aspect, there is provided a method of manufacturingat least one capacitor, wherein the capacitance of the capacitor may beadjusted by controlling the thickness of a dielectric layer. The methodincludes: providing a substrate; applying a first capacitor electrode onthe substrate; and applying an organic insulating layer on the firstcapacitor electrode. The organic insulating layer may be used as adielectric layer interposed between capacitor electrodes. The organicinsulating layer is preferably formed with a thickness of about 1 μm toabout 5 μm. In order to control the thickness of the dielectric layer ofthe capacitor, the organic solvent is applied onto a portion of, andpreferably onto the whole, first area in which the first capacitorelectrode is located, thereby reducing the thickness of the organicinsulating material. After reducing the thickness of the organicinsulating material, the second capacitor electrode is formed over theorganic insulating layer over at least a portion of the first area.Preferably, the thickness of the material that covers the firstcapacitor electrode is reduced to between about 50 μm and about 1000 nm,more preferably, between about 50 μm and about 500 nm. Preferably, thefirst capacitor electrode and the second capacitor electrode are eachformed with lengths of between about 50 μm and about 500 μm and withwidths of between about 50 μm and about 500 μm.

According to a seventh aspect, a plurality of functional layers isformed on a substrate and arranged in a matrix, each functional layerincluding a source electrode, a channel area, and a drain electrode. Thefunctional layers are covered by an organic insulating layer, and anorganic solvent is applied in first areas in which the channel areas arelocated, thereby reducing the thickness of the organic insulatingmaterial. Preferably, a gate electrode is formed over the organicinsulating material in the first area. Preferably, the organicinsulating material which covers the channel area is reduced to athickness of between about 50 μm and about 1000 nm, more preferably,between about 50 μm and about 500 nm. Preferably, each of the channelareas is formed with a length of between about 5 μm and about 500 μm,and a width of between about 10 μm and about 500 μm.

According to an eighth aspect, there is provided a method ofmanufacturing a pixel defining layer for a display application. Themethod for manufacturing a plurality of pixel defining layers,preferably arranged in a matrix, includes: providing a substrate;applying a first electrode onto the substrate; applying an organicinsulating layer over the first electrode; and applying an organicsolvent into a plurality of first areas or pixel areas, thereby exposingthe first electrode layer in the plurality of pixel areas andaccumulating dissolved organic insulating material in areas neighboringthe plurality of pixel areas, thereby forming a pixel defining layer.Preferably, the pitch between adjacent first areas or pixel areas, whichis the distance between the centers of adjacent pixel areas, ranges frombetween about 10 μm to about 150 μm, more preferably, between about 40μm and about 100 μm.

According to a ninth aspect, there is provided a method of manufacturingcontact holes, via holes, and/or through holes in insulating layers. Themethod includes: providing a substrate, applying an organic insulatinglayer on the substrate; and applying an organic solvent onto a firstarea of the organic insulating layer in which a contact hole is to beformed. In order to reduce the resistance of the contact hole, a plasmaetching treatment, preferably using argon plasma in a microwave plasmadevice, is provided. The plasma process can be carried out on thesubstrate comprising a plurality of contact holes, preferably arrangedin matrix. The plasma process is carried out for a time of about 10seconds to about 120 seconds. The power preferably ranges from betweenabout 20 W and about 100 W. The gas flow preferably ranges between about10 ccm to about 50 ccm. The electrode distance preferably ranges betweenabout 15 mm and about 75 mm. The pressure preferably ranges betweenabout 0.01 mbar and about 0.1 mbar. The substrate temperature ispreferably room temperature.

The following general remarks apply to the first through ninth aspects.Preferably, the organic insulating layer includes an organic insulatingmaterial that is completely formed of an organic insulating material.Preferably, the organic insulating layer is formed by spin coating, dipcoating, screen printing, or offset printing. Preferably, the organicinsulating layer is formed with a thickness of between about 0.1 μm andabout 3 μm. Preferably, the organic insulating layer includes an organicinsulating material that includes a uniform thickness on the substrateonto which the layer is applied.

The organic insulating material may comprise a material selected fromthe group consisting of polyvinylphenol, polyvinyl alcohol,polyethylene, polystyrene, poly(methylmethacrylate),poly(butylmethacrylate), poly(cyclohexylmethacrylate), polyisobutylene,and polypropylene.

A fluorinated organic polymer may be used as the organic insulatingmaterial for the layer. The organic insulating material may comprise amaterial selected from the group consisting of polyhexafluoropropene,fluorinated poly-para-xylene, fluorinated polyaryl ether ketones,fluorinated polyalkyl ethers, fluorinated polyamide, fluorinatedethylene/propylene copolymer,poly-(1,2-difluoromethylene)-perfluoro-tetrahydrofuran, andpolytetrafluorethylene.

The organic solvent may be a non-polar solvent. Preferably, the organicsolvent comprises a solvent selected from the group consisting ofmethylene chloride, tetrahydrofuran, xylene, n-hexane, toluene,cyclohexane, anisole, 3,4-dimethylanisole, 1,2-dichlorobenzene,tetralin, 1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene,1,3,5-trimethylbenzene, methyl benzoate, ethyl benzoate,perfluoroheptane, perfluorooctane, perfluorononane, perfluorodecane,perfluoroundecane, perfluorododecane, perfluorodecalin,perfluoromethyldecalin, perfluoro-dimethyl ether,perfluoro-tetrahydrofuran, perflouromethyltetrahydrofuran,perflouro-ethyltetrahydrofuran, perflouro-dipropyl ether,perflourodiisopropyl ether, perfluoro-ethylpropyl ether,perfluoro-2-butyltetrahydrofuran, perfluorinated saturated tertiaryamines, heptacosafluorotributylamine, and methoxynonafluorobutane.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages will become more apparent bydescribing in detail exemplary embodiments thereof with reference to theattached drawings in which:

FIGS. 1A-1D illustrate cross-sectional views of an embodiment of a bankstructure of a substrate that can be used for the manufacture of anorganic light emitting diode (OLED);

FIGS. 2A-2D illustrate an embodiment of a method of manufacturing a bankstructure on a substrate that can be used for the manufacture of anOLED;

FIGS. 3A-3E illustrate an embodiment of a method of manufacturing anOLED;

FIGS. 4A-4E illustrate an embodiment of a method for encapsulating twoparallel conductive lines;

FIGS. 5A-5F illustrate an embodiment of a method of manufacturing aplurality of organic thin film transistors coupled to a pixel electrode;

FIGS. 6, 7A, and 7B illustrate an embodiment of a method ofmanufacturing an electrophoretic display;

FIGS. 8A-8G illustrate another exemplary embodiment of a method ofmanufacturing an OLED;

FIGS. 9A and 9B illustrate an embodiment of a method of manufacturing acapacitor;

FIGS. 10A and 10B illustrate an embodiment of a method of manufacturingan organic thin film transistor;

FIGS. 11A and 11B illustrate an embodiment of a method of manufacturinga pixel defining layer; and

FIGS. 12A-12E illustrate an embodiment of a method of manufacturing aplurality of contact holes.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Hereinafter, certain embodiments will now be described more fully withreference to the accompanying drawings, which illustrate exemplaryembodiments. In general, it shall be noted that reference characters arenot attached to every element in every drawing for clarity, but onlywhen an element is shown the first time. Therefore, it should beunderstood that elements having the same hatching represent the samefunctional elements.

FIGS. 1A to 1D are cross-sectional views an embodiment of a bankstructure on a substrate employed in the manufacture of an organic lightemitting diode (OLED). The units of the horizontal axes are μm and theunits of the vertical axes are μm in FIGS. 1A-1D.

FIG. 1A shows a cross-sectional view an embodiment of the bank structureof the substrate that can be used for the manufacture of an OLED. FIG.1B shows an enlarged view of the bank structure of the substrate of FIG.1A. In order to obtain a substrate having the bank structure that can beused for an OLED manufacturing process, the illustrated embodimentprovides a supporting substrate onto which a layer of an organicinsulating material is applied. In some embodiments, the layer of theorganic insulating material is a substantially continuous layer. Inorder to obtain the bank structure, an organic solvent (not shown) isapplied onto a plurality of first areas 4 that define the pixel areas inthe OLED manufacturing process, as illustrated in FIG. 1B. The organicsolvent (not shown) dissolves the organic insulating material in thepixel areas and accumulates the dissolved organic insulating material ina second area 5 adjacent to the pixel area. The second area 5 ischaracterized as a non-pixel area. Depending on the amount of organicsolvent applied and the distance between adjacent pixel areas, thenon-pixel area 5 can comprise a single ridge of organic insulatingmaterial (see FIGS. 1C and 1D), or by a double ridge of organicinsulating material (see FIGS. 1A and 1B). Furthermore, it is possibleto form very steep protrusions or ridges in the non-pixel areas 5,wherein the protrusions have a height that can be up to ten times higherthan the thickness of the organic insulating material in the pixel areas4. Furthermore, it is possible to completely remove the organicinsulating material from the pixel areas 4 or to only reduce and controlthe thickness of the layer in the pixel areas 4 to a certain amount.

FIGS. 2A-2D illustrate an embodiment of a method of manufacturing a bankstructure on a substrate that can be used for the manufacture of anOLED. First, referring to FIG. 2A, a substrate 1, which is in generalpreferably formed of glass or a plastic substrate and which preferablycomprises a planar top surface, is provided. Referring to FIG. 2B, anorganic insulating layer 2 is applied on the substrate 1. In someembodiments, the organic insulating layer 2 is applied over the wholesubstrate. Preferably, the organic insulating layer 2 has a generallyuniform thickness on the substrate 1. Referring to FIG. 1C, an organicsolvent 3 is applied onto a plurality of first areas 4 of the organicinsulating layer 2, each first area corresponding to a pixel area. Theorganic solvent 3 forms a first groove g1 by dissolving the organicinsulating material of the first area 4. Then, the dissolved organicinsulating material is accumulated on an edge of the first area 4 and/ora second area 5 adjacent to the first area 4 to form at least oneprotrusion P. Referring to FIG. 2D, the thickness reduction in the firstarea 4 corresponds to the amount of applied organic solvent 3. Asillustrated in the left first area 4 in FIG. 2D, the layer thickness hasbeen reduced, but the organic insulating material has not beencompletely removed from the left first area 4. However, due to the useof a larger amount of the organic solvent 3 applied to the right firstarea 4, the organic insulting material has been completely removed fromthe right first area 4. The area between adjacent first areas 4 formsthe second area 5 that contains accumulated insulating material. Aplurality of protrusions P is formed on the second area 5 due to theaccumulation of the dissolved organic insulating material. Therefore,the layer thickness of the second area 5 is increased while the layerthickness of the first areas 4 is decreased as the organic solvent isapplied. Herein, the first area 4 corresponds to the pixel area and thesecond area 5 corresponds to the non-pixel area.

FIGS. 3A-3E illustrate an embodiment of a method of manufacturing anOLED. First, a substrate 1 is provided as shown in FIG. 3A. Then, afirst electrode 6, for example, an indium-tin oxide (ITO) layer isapplied onto the substrate 1 as shown in FIG. 3B, and the firstelectrode layer 6 is covered by an organic insulating layer 2 as shownin FIG. 3C. Then, an organic solvent (not shown) is applied onto aplurality of first areas 4 of the organic insulating layer 2.Preferably, the organic solvent is applied onto first areas 4 of theorganic insulating layer 2 that correspond to respective pixel areas,and are arranged in a matrix. The amount of organic solvent iscontrolled such that the organic insulating material is completelydissolved and removed from the first areas 4, thereby exposing the firstelectrode layer 6 in each of the first areas 4. Thus, each of the firstareas 4 includes a first groove g1.

As shown in FIG. 3D, a second area 5 of the organic insulating layer 2that is adjacent to the first area 4 includes a protrusion P due to theaccumulation of the dissolved organic insulating material thereon. Inthe present embodiment, the second area 5 may correspond to a non-pixelarea. According to the present embodiment, the patterning of a bankstructure consisting of an insulating material in the non-pixel areascan be easily carried out by the operations of applying an organicinsulating layer 2 and applying an organic solvent onto the respectiveareas in which the layer thickness is to be reduced or completelyremoved. Therefore, cost intensive process operations, such asphotolithography processes, can be avoided.

As shown in FIG. 3E, the organic electroluminescent device can befinished by the application of an organic electroluminescent layer 7 anda second electrode 8. Optionally, a hole transport layer 20 can beformed between the first electrode 6 and the organic electroluminescentlayer 7.

FIGS. 4A-4E illustrate an embodiment of a method of encapsulating twoparallel conductive lines. Display devices such as OLED devices includea plurality of conductive lines such as data lines, gate lines, andconnecting lines between transistors, capacitors, and light-emittingdiodes. In particular, in the case of crossing conductive lines, atleast one of the conductive lines can be encapsulated in order toprevent a short circuit between the crossing conductive lines.

According to the illustrated embodiment, a substrate 1, which is usedfor a display device, is provided as shown in FIG. 4A. Then, an organicinsulating layer 2 is applied on the substrate 1. As shown in FIG. 4C,at least one conductive lines 9 is applied onto the organic insulatinglayer 2. The illustrated embodiment comprises a total of threeconductive lines 9. In order to encapsulate the left and the middleconductive lines 9, an organic solvent (not shown) is applied in a firstarea 4 between the left and the middle conductive lines 9. Referring toFIG. 4D, the organic solvent dissolves the organic insulating materialin the first area 4 to form a first groove g1. Then, the dissolvedorganic insulating material is accumulated in a periphery portion of theconductive lines 9, that is, in second areas to which the organicsolvent is not applied to form protrusions P, thereby, encapsulating theleft and the middle conductive lines 9 with organic insulating material.After the complete encapsulation of the left and the middle conductivelines 9, it is further possible to apply a crossing conductive line 9 asshown in FIG. 4E. The above-described method is preferably used for themanufacture of an organic electroluminescent display.

FIGS. 5A-5F illustrate an embodiment of a method of manufacturing aplurality of organic thin film transistors (OTFTs) coupled to a pixelelectrode. Each OTFT includes a source electrode 11, a channel area 12comprising a semiconductor material, a drain electrode 13, an organicinsulating layer 2 and a gate electrode 15.

In order to cost effectively manufacture a structure comprising aplurality of the OTFTs that are each coupled to a respective pixelelectrode 14, a substrate 1 is provided as shown in FIG. 5A. As shown inFIGS. 5B and 5C, a plurality of source electrodes 11, drain electrodes13, pixel electrodes 14, and channel areas 12 are formed on thesubstrate 1. An organic insulating layer 2 is applied on the substrate1, thereby, covering the plurality of source electrodes 11, channelareas 12, drain electrodes 13, and pixel electrodes 14. Then, as shownin FIG. 5E, each of the gate electrodes 15 is formed on the organicinsulating layer 2 on an area that is located over the channel area 12for each OTFT. In order to expose each of the pixel electrodes 14 and toencapsulate each of the gate electrodes 15, an organic solvent (notshown) is applied onto the plurality of first areas 4 defined by thepixel electrodes 14. The organic solvent dissolves the insulatingmaterial in the first area 4, thereby, exposing the pixel electrode 14and further accumulating the organic material in peripheral second areasof the pixel portions, e.g., in the portions in which the gateelectrodes 15 are located, and thereby, encapsulating the gateelectrodes 15.

FIGS. 6, 7A, and 7B illustrate an embodiment of a method ofmanufacturing an electrophoretic display. FIG. 6 illustrates a top viewof one pixel of an electrophoresis display that includes a plurality ofpixels arranged in a matrix, wherein each pixel includes the OTFTcomprising a source electrode 11′, a drain electrode 13′, a channel area12′ located between the source electrode 11′ and the drain electrode13′, and a gate electrode, which is insulated from the channel area 12′.The gate electrode is coupled to one of a plurality of scan lines, andthe source electrode 11′ is coupled to one of a plurality of data lines21, wherein the electrophoresis display comprises a plurality of datalines 21 and scan lines intersecting with each other, thereby, definingthe plurality of pixels. Furthermore, each pixel includes a pixelelectrode 14.

FIG. 7A illustrates a first structure comprising an OTFT including thesource electrode 11, the channel area 12, the drain electrode 13, andthe drain electrode 13 coupled to the pixel electrode 14. Only the gateelectrode is coupled to the pixel electrode 14. The first structure canbe obtained by the method described above in connection with FIG. 5, oras will be described later in connection with FIG. 8. Furthermore, asecond structure including a flexible substrate 22, an activeelectrophoretic layer 23, and a protection or adhesion layer 24 isprovided as shown in FIG. 7A.

As shown in FIG. 7B, the electrophoretic display is manufactured byforming the second structure on the first structure illustrated in FIG.7A. Accordingly, the electrophoretic display comprises a plurality ofpixels, each pixel including an OTFT and an electrophoretic lightemitting device. The OTFT comprises the source electrode 11, the channelarea 12, the drain electrode 13, and the gate electrode 15, wherein thesource electrode 11 is coupled one of the plurality of data lines 21(FIG. 6) and the gate electrode 15 is coupled to one of the plurality ofscan lines. The electrophoresis display includes the pixel electrode 14,the protection or adhesion layer 24, the active electrophoretic layer23, and the flexible substrate 22. Furthermore, the electrophoreticdisplay may include a facing electrode, the second layer from top inFIG. 7B but not having reference number.

FIGS. 8A-8G illustrate another exemplary embodiment of a method ofmanufacturing an OLED. The OLED has a pixel area including an OTFT thatis coupled to the pixel electrode 14. First, as shown in FIGS. 8A to 8C,a substrate 1 is provided, and for each pixel area, a source electrode11, a drain electrode 13, a channel area 12 consisting of asemiconductor material, and the pixel electrode 14 are formed on thesubstrate 1 to form each pixel. Then, as shown in FIG. 8D, a organicinsulating layer 2 is applied on the substrate 1, thereby, covering aplurality of source electrodes 11, channel areas 12, drain electrodes13, and pixel electrodes 14. As illustrated in FIG. 8E, the organicinsulating layer 2 may include a first area 4 located on the pixelelectrode 14 and a second area 5 located on the source electrode 11, thechannel area 12, and the drain electrode 13. Returning to FIG. 8D, anorganic solvent (not shown) is applied onto the plurality of first areas4 of the organic insulating layer 2, thereby, exposing the pixelelectrode 14. Thus, each first area 4 includes a first groove g1 inwhich the pixel electrode 14 is exposed. The dissolved organicinsulating material is accumulated on the second area 5 that is adjacentto the first area 4. Accordingly, the second area 5 includes aprotrusion P in which the thickness of the organic insulating layer 2 isincreased. Furthermore, the second area 5 may include at least twoprotrusions P by accumulating the dissolved organic insulating materialfrom adjacent first areas 4, thereby forming a second groove g2 betweenthe at least two adjacent protrusions P. The second area 5 forms adouble ridge structure comprising the second groove g2 in its middleportion. Referring to FIG. 8F, a gate electrode 15 is formed in thesecond groove g2. As shown in FIG. 8G, a passivation layer 17 is appliedon the gate electrode 15. The structure as illustrated in FIG. 8G can beused for further manufacturing process operations for an organicelectroluminescent display, an electrophoretic display, and the like.The above-described method is preferably used for the manufacture of anOLED display.

FIGS. 9A and 9B illustrate an embodiment of a method of manufacturing acapacitor. Usually, for the manufacture of an active matrix organicelectroluminescent display, each pixel circuit comprises at least onecapacitor. Therefore, a plurality of capacitors is manufactured for anorganic electroluminescent display. A large capacitance can result froma very thin insulating layer between two capacitor electrodes. However,according to conventional methods of applying an insulating layer, it isdifficult to control the thickness of the insulating layer to a very lowamount. Embodiments of the present method permit forming an organicinsulating layer in which the thickness can be reduced and controlled toa desired amount by use of an organic solvent.

As shown in FIG. 9A, a substrate 1 comprising a first capacitorelectrode 18 is provided. Then, an organic insulating layer 2 is formedon the first capacitor electrode 18. In order to reduce the layerthickness of the organic insulating layer 2, an organic solvent (notshown) is applied to a first area 4 of the organic insulating layer 2,thereby, reducing and controlling the layer thickness to a desiredamount. Then, as shown in FIG. 9B, the second capacitor electrode 19 isapplied to the first area 4, thereby, forming a capacitor. Suchcapacitor is preferably used for the manufacture of an active matrixorganic electroluminescent display.

FIGS. 10A and 10B illustrate an embodiment of a method of manufacturingan organic thin film transistor. For the manufacture of an active matrixorganic electroluminescent display, a plurality of thin film transistorsis manufactured for each pixel. In order to obtain a uniform brightnessover the whole active matrix organic electroluminescent display, it isdesirable to form a plurality of the organic thin film transistorshaving uniform electrical characteristics, and it is also desirable toform the gate electrodes 15 with an uniform distance from the channelarea 12, which is insulated by a gate insulating layer, on the substrate1.

As shown in FIG. 10A, the substrate 1 comprises a source electrode 11, achannel area 12 comprising a semiconductor material, and a drainelectrode 13. Then, an organic insulating layer 2 is applied on thesubstrate 1 to cover the source electrode 11, the channel area 12, andthe drain electrode 13. The thickness of the organic insulating layer 2is greater than about 1 μm. Then, an organic solvent (not shown) isapplied on the layer in a first area 4 that is located above the channelarea 12, thereby, reducing and controlling the thickness of the organicinsulating layer 2 to less than about 1 μm. As shown in FIG. 10B, afirst groove g1 is formed in the first area 4 of the organic insulatinglayer 2 to which the organic solvent is applied, and a protrusion P isformed in a second area 5 adjacent to the first area 4, to which theorganic solvent is not applied. Then, the gate electrode 15 is appliedonto the first groove g1. The above-described method for the manufactureof the organic thin film transistor is preferably used for themanufacture of an organic electroluminescent display.

FIGS. 11A and 11B illustrate an embodiment of a method of manufacturinga pixel defining layer. During the manufacture of an active matrixorganic electroluminescent display, it is usually desirable to form apixel defining layer.

According to the illustrated embodiment, a substrate 1 including a firstelectrode 6 is provided. As shown in FIG. 11A, an organic insulatinglayer 2 is applied on the first electrode 6. Then, an organic solvent(not shown) is applied to a first area 4 of the organic insulating layer2. The first area 4 corresponds to a pixel area in the active matrixorganic electroluminescent display. As shown in FIG. 11B, the organicsolvent dissolves the organic insulating material in the first area 4,thereby, forming a first groove g1 and exposing the first electrode 6 atthe bottom of the first groove g1. The dissolved organic insulatingmaterial is accumulated on a second area 5 adjacent to the first area 4so as to form a protrusion P, and thus, the pixel defining layer isformed.

The above-described method of forming the pixel defining layer ispreferably used for the manufacture of an active matrix organicelectroluminescent display. In general, an organic electroluminescentdisplay comprises a plurality of pixels arranged in a matrix, each pixelcomprising at least one organic thin film transistor, wherein a sourceelectrode of the organic thin film transistor is coupled to a data line,a gate electrode of the organic thin film transistor is coupled to aselect line of the organic electroluminescent display, and wherein thedrain of the thin film transistor is coupled to a pixel electrode. Eachpixel further includes a facing electrode and an organicelectroluminescent layer. As mentioned above, each pixel may furtherinclude a pixel defining layer, and furthermore, it may be desirable toarrange contact holes in insulating layers, for example, to couple thedrain electrode with the pixel electrode.

FIGS. 12A-12E illustrate an embodiment of a method of manufacturing aplurality of contact holes according to the present invention. Asubstrate 1 that preferably comprises glass or plastic is provided, andan organic insulating layer 2 is applied on the substrate 1. Then, asshown in FIG. 12C, an organic solvent 3 is applied on the organicinsulating layer 2 onto a first area 4 in which a contact hole/via holeis desired. Accordingly, a first groove g1 is formed in the first area 4of the organic insulating layer 2 to which the organic solvent 3 wasapplied, and a protrusion P is formed in a second area 5, which isadjacent to the first area 4, and to which the organic solvent is notapplied. As shown in FIG. 12D, the organic insulating layer 2 issometimes not completely removed from the area where the contact hole isdesired because small amounts of organic insulating material remain inthe contact hole. In order to decrease the resistance of the contacthole, a plasma-etching process is performed to provide the structureshown in FIG. 12D. Therefore, the organic insulating layer 2 iscompletely removed from the contact holes.

Provided herein is a method of manufacturing an electronic deviceincluding a bank structure requires a fewer number of processes.Particularly, a direct patterning of an organic insulating layercomprising, for example, fluorinated organic polymers, is possible byusing an organic solvent to form a bank structure. Thus, the bankstructure can be easily formed for later printing processes in themanufacture of an electronic device such as an OLED that requires a bankstructure. Furthermore, embodiments of the method are roll to rollcompatible, therefore, flexible substrates are processable.

While certain embodiments have been particularly shown and described, itwill be understood by one of ordinary skill in the art that variouschanges in form and details may be made therein without departing fromthe spirit and scope of the present disclosure, the scope of which isdefined by the following claims.

1. A method of manufacturing an electronic device, the methodcomprising: providing a substrate; applying an organic insulating layercomprising an organic insulating material on the substrate; and applyingat least one conductive line onto at least one second area of theorganic insulating layer; and patterning the organic insulating layer byapplying an organic solvent to at least one first area of the organicinsulating layer, wherein in the patterning the organic insulatinglayer, dissolving the organic insulating material of the first area byapplying the organic solvent, and encapsulating the at least oneconductive line with the dissolved organic insulating material.
 2. Themethod of claim 1, wherein the organic insulating material comprises afluorinated organic polymer.
 3. The method of claim 2, wherein theorganic insulating material comprises a material selected from the groupconsisting of polyhexafluoropropene, fluoronated poly-para-xylene,fluorinated polyaryl ether ketones, fluorinated polyalkyl ethers,fluorinated polyamide, fluorinated ethylene/propylene copolymer,poly-(1,2-difluoromethylene)-perfluoro-tetrahydrofuran, andpolytetrafluorethylene.
 4. The method of claim 1, wherein the organicinsulating material comprises a material selected from the groupconsisting of polyvinylphenol, polyvinyl alcohol, polyethylene,polystyrene, poly(methylmethacrylate), poly(butylmethacrylate),poly(cyclohexylmethacrylate), polyisobutylene, and polypropylene.
 5. Themethod of claim 1, wherein the organic solvent comprises a non-polarsolvent.
 6. The method of claim 5, wherein the organic solvent comprisesa solvent selected from the group consisting of methylene chloride,tetrahydrofuran, xylene, n-hexane, toluene, cyclohexane, anisole,3,4-dimethylanisole, 1,2-dichlorobenzene, tetralin,1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene, 1,3,5-trimethylbenzene,methyl benzoate, ethyl benzoate, perfluoroheptane, perfluorooctane,perfluorononane, perfluorodecane, perfluoroundecane, perfluorododecane,perfluorodecalin, perfluoromethyldecalin, perfluoro-dimethyl ether,perfluoro-tetrahydrofuran, perfluoro-methyltetrahydrofuran,perfluoro-ethyltetrahydrofuran, perfluoro-dipropyl ether,perfluoro-diisopropyl ether, perfluoro-ethylpropyl ether,perfluoro-2-butyltetrahydrofuran, perfluorinated saturated tertiaryamines, heptacosafluorotributylamine, and methoxynonafluorobutane. 7.The method of claim 1, further comprising carrying out a plasma-etchingof the organic insulating layer.
 8. The method of claim 1, furthercomprising forming a first conductive layer on the substrate.
 9. Themethod of claim 8, wherein an organic insulating layer is applied ontothe substrate having a first conductive layer, and the organicinsulating layer is patterned by applying an organic solvent to theorganic insulating layer to expose the first conductive layer.
 10. Themethod of claim 9, further comprising forming an electroluminescentlayer on the exposed first conductive layer.
 11. The method of claim 8,wherein an organic insulating layer is applied onto the substrate havingthe first conductive layer, and the organic insulating layer ispatterned by applying an organic solvent to the organic insulating layernot to expose the first conductive layer.
 12. The method of claim 11,further comprising forming a second conductive layer on the patternedorganic insulating layer.
 13. The method of claim 1, wherein in thepatterning the organic insulating layer, the thickness of the organicinsulating layer is reduced in a plurality of first areas by applyingthe organic solvent in each of the first area, and the thickness of theorganic insulating layer is increased in each of second areas, which aredefined by an area between adjacent first areas, by accumulating theorganic insulating material, which is dissolved by the organic solventonto the second area.
 14. A method of manufacturing an organicelectroluminescent display, the method comprising: providing asubstrate; applying a source electrode, a channel area, a drainelectrode and a pixel electrode onto the substrate; applying an organicinsulating layer comprising an organic insulating material to cover thesource electrode, the channel area, the drain electrode and the pixelelectrode; and removing the organic insulating material of a first areaby applying an organic solvent to the first area of the organicinsulating layer corresponding to the top surface of the pixelelectrode.
 15. The method of claim 14, wherein the organic insulatingmaterial of the first area is removed by applying the organic solvent tothe first area so as to expose the pixel electrode.
 16. The method ofclaim 14, further comprising plasma-etching to expose the pixelelectrode.
 17. The method of claim 14, further comprising forming a gateelectrode on a second area of the organic insulating layer correspondingto the top surface of the channel area.
 18. The method of claim 17,wherein the organic solvent is applied onto the first area to dissolvethe organic insulating material and the dissolved organic insulatingmaterial covers the gate electrode after the gate electrode has beenformed on the organic insulating layer.
 19. The method of claim 17,wherein the organic solvent is applied onto the first area to dissolvethe organic insulating material, and the dissolved organic insulatingmaterial is accumulated on the second area adjacent to the first area,thereby, forming a gate electrode on the accumulated organic insulatingmaterial.